Device for taking samples of bottom sediments from water basins

ABSTRACT

A device for taking samples of bottom sediments from water basins includes at least one vertical sectional coring tube having a closed upper end provided with a check valve. The device includes, in the form of a cover, also a device for preventing the loss of a taken sample in the process of the device lifting, closing in a rest position the open lower end of the coring tube and being connected with the movable rod. The rod is secured by hinges to the carrying element. The upper end of the coring tube is secured to the carrying element.

This application is a continuation-in-part of application Ser. No.07/404,076, filed Sept. 7, 1989, and now abandoned.

FIELD OF THE INVENTION

The invention relates to the oceanographic instruments for investigatingproperties of substances and, more particularly, to devices for takingsamples of bottom sediments from water basins.

BACKGROUND OF THE INVENTION

Known in the prior art is a device for taking samples of bottomsediments from water basins, comprising a vertical coring tube with aclosed upper end provided with a check valve, a ballast weight on theupper end of the coring tube and the side stationary supports (cf. USSRInventor's Certificate No. 1,013,810, class G01N, 1/10, published in1983).

However, under the conditions of rough water in water basins such adevice fails to provide a guaranteed sampling as water masses in thevolume of a wave move upwards at a speed greater than that of the deviceproper, because of which the check valve in the upper end of the coringtube gets opened and the taken sample is partially or even completelylost. Under the conventional conditions the sample is retained in thecoring tube due to the fact that with the device being lifted, the checkvalve is closed and the reduced pressure is built up in the spacebetween the closed upper end of the coring tube and the sample containedtherein.

Also known in the prior art is a device for taking samples of bottomsediments from water basins, comprising a vertical coring tube with aclosed upper end provided with a check valve and a means for preventingthe loss of a taken sample in the process of the device lifting (cf.USSR Inventor's Certificate No. 623,128, class G01N, 1/04, published in1978).

In the known device the coring tube is made in the form of twoconcentrically installed tubes, the internal tube being intended forfilling with a taken sample. As to a means for preventing the loss of ataken sample, a valve is used. The valve is installed at the cuttingshoe and is made in the form of two flaps closing under the action ofthe springs. Before the device sinking onto the bottom of a water basinthe flaps are cocked. The device sinks in the soil under the action ofthe weight thereof. The column of the soil, moving upwards in the cavityof the tube, completely opens the valve flaps, releasing them from thecocking stop, and fills the internal tube. While lifting the device thevalve flaps close under the action of the springs and the weight of thetaken sample. The known device prevents the loss of a taken sample inthe process of lifting. However, the natural structure of bottomsediment layers is disturbed. This results from the following. The valveflaps are, prior to sampling, in a half-open position and opencompletely only under the action of the force developed by the column ofthe sample moving upwards. The weak layers (especially the surfacelayer) are not able to stand the force needed for the complete openingof the flaps, in the zone of the valve flaps the section for the samplepassing is decreased and as a result, the compression and intermixing ofthe sample takes place, leading to the disturbance of the initialstructure of the sample layers.

The invention is aimed at providing a device for taking samples ofbottom sediments from water basins with a means for preventing the lossof a taken sample in the process of the device lifting of such a designwhich will ensure an undisturbed natural structure of the bottomsediment layers in the taken sample.

SUMMARY OF THE INVENTION

It is an object of the invention to improve the representativeness ofthe taken samples.

It is another object of the invention to improve the representativenessof the taken samples under adverse weather conditions.

The nature of the invention consists in that in a device for takingsamples of bottom sediments from water basins, comprising a verticalcoring tube with a closed upper end provided with a check valve and ameans for preventing the loss of a taken sample in the process of thedevice lifting, according to the invention, the means for preventing theloss of a taken sample is made in the form of a cover, secured to amovable forked rod. The forked rod has two upper ends and one lower endand the length exceeding the length of the coring tube. The upper partof the rod is branched in the form of two branches, having said upperends of the rod, the lower part is unbranched, having said lower end ofthe rod. The upper ends of the branches are secured by means of thehinges to the carrying element, to which by means of its upper end alsothe coring tube is secured. The upper ends of the branches are securedsymmetrically relative to the coring tube and with the distance fromeach other exceeding the diameter of the coring tube. The cover issecured by means of the hinges to the branches at the places beingbefore the place where the branched part of the rod goes over to theunbranched one, so that in a rest position the cover closes the lowerend of the coring tube. In a rest position the lower end of the rod isbelow the level of the lower end of the coring tube and has a plate,secured therewith by means of a hinge. To enable us to take parallelsamples, the device may comprise more than one coring tube.

The cover may suitably be made in the form of a plate with aperpendicular semicircular bead suiting the external surface of thecoring tube from the place of the securing of the cover to the rod.

It is desirable to bend the unbranched part of the rod relative to thebranched one with an angle α<180° in the plane of displacement of therod with the cover while opening the lower end of the coring tube.

It is advisable to supply the branches of the rod with the locks,secured by means of the rods to the branches above the places where thecover is secured so that in a rest position the locks catch the coringtube.

It is also adviable that the device for taking samples of bottomsediments should be provided with at least three supports having upperand lower ends and the length exceeding the length of the coring tube,placed uniformly around the coring tube and secured by their upper endsto the carrying element.

A device for taking samples of bottom sediments from water basins madeaccording to the present invention makes it possible to takerepresentative samples of bottom sediments even under adverse weatherconditions (in case of rough water and craft motions), when the speed ofupward movement of water masses exceeds the lifting speed of the devicewith a taken sample. In the case of disappearance of the reducedpressure in the upper part of the coring tube, the taken sample ofbottom sediments is reliably held by the cover, which closes the lowerend of the coring tube. The device ensures an undisturbed naturalstructure of bottom sediment layers in a taken sample.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in greater detail with reference tospecific embodiments thereof, taken in conjunction with the accompanyingdrawings, wherein:

FIG. 1 is a general view, partly in section, illustrating a device fortaking samples of bottom sediments from water basins;

FIG. 2 is a section taken on line II--II of FIG. 1;

FIG. 3 is a section taken on line III--III of FIG. 1;

FIG. 4 diagrammatically illustrates a device at the moment when theplate comes in contact with the bottom of a water basin in the processof the device sinking;

FIG. 5 is the same of FIG. 4 at the moment of taking a sample.

DETAILED DESCRIPTION OF THE INVENTION

A device for taking samples of bottom sediments from water basins,illustrated in FIGS. 1, 2 and 3, comprises a vertical sectional coringtube 1 with a closed upper end in which a check valve 2 is built and anopen lower end 3, a carrying element 4, being at the same time the mainballast weight, to which by means of a strip 5 and the bolts 6 thecoring tube 1 by its upper end is secured, an additional ballast weight7 consisting of a set of removable disks installed on the uprights 8,the supports 9, at least three in quantity, having the length exceedingthe length of the coring tube 1, placed uniformly around the tube 1 andsecured by their upper ends to the carrying element 4, the bars 10 bymeans of which the device is suspended to a rope 11. As a means forpreventing the loss of a taken sample in the process of the devicelifting the device comprises a cover 12, made in the form of a plate 13with a perpendicular semicircular bead 14. The cover 12 is secured tothe forked rod 15, which has a branched upper part with two branches15', having two upper ends of the rod 15, and an unbranched lower part15", having the lower end of the rod 15. The branches 15' are secured bytheir upper ends to the carrying element 4 by means of the hinges 16symmetrically relative to the coring tube 1 and with the distance fromeach other exceeding the diameter of the coring tube 1. The cover 12 issecured by means of the hinges 17 to the branches 15' at the placesguaranteeing that in a rest position the plate 13 of the cover 12 fitsclosely the lower end 3 of the coring tube 1. To the lower end of therod 15 by means of a hinge 18 a plate 19 is secured. The unbranched part15" of the rod 15 is bent relative to the branched part 15' with anangle α<180°. Locks 20 may optionally be used to catch the coring tubeduring ascent. If used, the locks 20 are made, for example, in the formof spring-loaded tongues and are secured to the branches 15' by means ofthe rods 21 above the hinges 17 so that in a rest position, with thecover 12 closing the ends of tube 11, locks 20 catch the coring tube 1;this position is shown in FIG. 1 and is position 3 of FIG. 3.

The device for taking samples of bottom sediments from water basinsoperates in the following manner.

In a rest position the cover 12 closes the lower end 3 of the coringtube 1 (FIG. 4). While sinking the device to the bottom of a waterbasin, the position of the cover 12 depends on the speed of sinking, theweights of the cover 12, the rod 15 and the plate 19. Before coming incontact with the bottom, the inclined position of the rod 15 assists inthe sliding of the plate 19 along the bottom of the water basin. At thesame time, together with the rod 15 moves also the cover 12 connectedwith it and the lower end 3 of the coring tube 1 begins to open andopens completely during further device sinking. The supports 9 preventthe device from tipping. Now the sampling takes place (FIG. 5). Afterthe sample is taken, the device is lifted by means of the rope 11. Thecheck valve 2 in the upper end of the coring tube 1 gets closed. Areduced pressure is built up between the upper end of the coring tube 1and the column of the sample due to which the taken sample is retainedin the coring tube 1. While the device lifting, the closing of the lowerend 3 of the coring tube 1 with the cover 12 starts, contributing to theaction of the weights of the rod 15, the cover 12 and the plate 19, thelatter being additionally acted upon by the dynamic pressure of watercolumn. From the moment when the plate 19 is pulled off from the bottomof the water basin the plate 13 of the cover 12 fits closely the lowerend 3 of the coring tube 1, closing it completely.

The invention as used and described with reference to FIGS. 4 and 5 iswithout the optional locks 20 being present in the structure. If locks20 are used and present in the structure, the locks 20 are initially inposition 1 as shown in FIG. 3, and thereby do not interfere with thefunction of the structure during descent and sample taking. Whileclosing the cover 12 during ascent, the locks 20 catch the coring tube 1and close up (FIG. 3) by moving from position 1, through position 2, andinto position 3. This ensures no loss of the taken sample even in caseof rough water in the water basin. The locked position 3 is alsoillustrated in FIG. 1.

The invention has been described in detail with particular reference topreferred embodiments thereof, but it will be understood that variationsand modifications can be effected within the spirit and scope of theinvention.

What is claimed is:
 1. A device for taking samples of bottom sedimentsfrom water basins, said device comprising:at least one vertical coringtube; sections of said coring tube arranged in succession one afteranother longitudinally of said tube; a closed upper end of said tube; acheck valve built in said upper end; an open lower end of said tube; acarrying element, said upper end of said tube being secured to saidcarrying element; a forked rod having a branched upper end and anunbranched lower end and the entire length exceeding the entire lengthof said tube; said branched upper part of said rod having two brancheswith upper ends of said rod; said unbranched lower part of said rodhaving a lower end of said rod; said branches of said branched part,pivotally secured by said upper ends to said carrying elementsymmetrically relative to said tube and with the distance from eachother exceeding the diameter of said tube; a cover, pivotally secured tosaid branches at the places guaranteeing that in a rest position saidcover closes said lower end of said tube; said lower end of said rod,being in a rest position below the level of said lower end of said tube;a plate, pivotally secured to said lower end of said rod.
 2. A deviceaccording to claim 1, wherein said cover is made in the form of a platewith a perpendicular border edge being semi-circular from the placewhere said cover is secured to said rod and suiting the external surfaceof the coring tube.
 3. A device according to claim 1, wherein saidunbranched part of said rod is bent relative to said branched part withan angle α<180° in the plane passing the vertical axis of said tube andbeing transverse to the plane of said branched part.
 4. A deviceaccording to claim 1, wherein said branches of said branched part ofsaid rod are supplied with locks secured by means of rods to saidbranches above the places where said cover is secured, so that in a restposition said locks catch said coring tube.
 5. A device according toclaim 1, which includes at least three supports, having upper and lowerends and the length exceeding the length of said coring tube placeduniformly around said tube and secured by said upper ends to saidcarrying element.